Temperature responsive regulating valve



Patented May 3, 1932 UNITED STATES PATENT' OFFICE JOHN F. HOFFMAN, OFOMAHA, NEBRASKAgASSIGNOR 'I.O BAKER ICE MACHINE CO.

INC., 01 OMAHA, NEBRASKA, A CORPORATION OF NEBRASKA TEMPmTUBE BESPOHSIVEREGULATING VALVE Application filed April 21,

My invention'relates to refrigerating apparatus and more particularly toapparatus of that character wherein a low boiling point liquid, such asanhydrous ammonia, is compressed and circulated through condensing andcooling coils to effect temperature equalization by expansion andevaporationpf the refrigerating agent in the cooling co ls, theprincipal object of the present inventlon being to control supply of therefrlgeratlng agent to the cooling 0011 by diiferentlal 1n temperatureat the outlet end of the coil.

' fluid influenced by changes in temperature of the refrigerating agentas at the outlet end of the coil, the changes in temperature of therefrigerating agent at the inlet end of the coil might cause the agentto exert changing pressure influences opposed to the influence of thevalve-controlling fluid. Further objects of the device, therefore, areto prevent interfer-. once by the refrigerating agent in a coil with thesupply-controlling means, and to effect an exchange of temperaturebetween the coilcontained refrigerating agent and the supplycontrollingfluid whereby a balance willbe -produced to offset the changes intemperature of the refrigerating agent.

The device is to be understood to be installed in a refrigerating systemcomprising means for delivering a refrigerant such as ammonia to a coilfor expansion therein to withdraw heat from the coil and the atmospheresurrounding the same; the system including also a compressor for settingup a vacuum in the return line for removing the expanded refrigerant andconditioning the same for another cycle of operation. Such constructionand since they'do notform part of the present invention they are notillustrated or described. 1

The present application is a continuation in part of my copendingapplication Serial featuresof the system may be of any desired 1928.Serial No. 271,754.

N 0. 209,690, in which a suitable refrigerating system is illustratedand described in detail, said application disclosing the supply-controlmeans herein more particularly described and claimed.

In accomplishing the above and other objects of the invention I haveprovided improved details of structure, the preferred forms of which areillustrated in the accompanying drawing, wherein:

The figure is a view partly diagrammatic and fragmentary, of arefrigerating coil and the inlet and outlet thereof, and a centralvertical section of my improved supply-control device installed infunctioningrelation with said inlet and outlet.

Referring in detail to the drawing:

1 deslgnates a supply line for .conducting an expansible refrigerantsuch as ammonia to'the inlet end 2 of a coil 3, and 4 designates asuction orreturn line connected to the out let end 5 of the coil. Therefrigerant passmg through the coil expands there n, exchanging heatwith the coil and' with the" atmospherein a compartment in which the 76coil may be located. The supply of refrigerant isordinarily controlledby amanu'ally operated valve, such as 6, in the supply line, forreducingzjincreasing or shutting off the supply suitably to produce ades red degree of cold in the compartment, or for maintaining a desiredtemperature. as well understood. The temperature of the refrigerant atthe outlet end of the coil is one factor indicating the temperaturecondition of the compartme nt for guidance in the manipulation of thevalve 6.

In order to control the supply automatically, I provide a temperaturecontrolled valve ind cated generally by the housing 7 interposed in thesupply line 1 adiacent the inlet end 2 of the coil. and comprising-abody member 8 and its cap 9. Formed. in the body 8 at one side thereofis a chamber "-10 into which the'supply line delivers. A screen 11 issupported in the chamber by a plug 12 which closes its open lower end.

Leading from the chamber 10 is a duct 13 which opens to a chamber 14formed partly the body 8 and partly within a cap suspended from the body8 by bolts 16.

The chamber 14'c0mmunicates through a throat 17 with a chamber 18 in thebody 8, the upper part of the chamber being preferably enlarged at 19 toprovide a substantial area of contact of refrigerating agent with adiaphragm 20 inter osed between the body 8 and the cap 9 and eld inplace by the bolts 21 which attach the cap 9' to the body 8.

A duct 22 leads from the chamber 18 to conduct refrigerating agent fromthe chamber to the coil 3.

' The ends of the supply line between,which the valve is interposed areconnected with the opposite sides of the valve by collars 23 and 24respectively threaded on the supply line portions 25 and 25' and havingflanges 26 engaging similar annular grooves 27 in the body.

Extending through the throatsl7 into the chamber 18 is a tube 28 havinga head 29 clamped against the top of the chamber 14 by a collar 30threaded into the upper portion of the chamber above the outlet of theduct 13.

Supported on the bottom of the cap 15 about a boss 31 is an expansionspring 32 carrying a seating plate 33 which supports a valve ball 34within the collar 30, and urges the ball to contact with the open lowerend of the tube 28, thereby constituting the end of the tube a valveseat.

Supported on the ball 34 and extending through the bore of the tube 28is a squared pin 35. I

Slidable on the upper end of the tube 28 is a sleeve 36 having a roundedhead 37 engaging the diaphragm 20 at its upper face and contacted by thesquared pin on its under face. The sleeve 36 is provided with portopenings 38 and the tube 28 with openings 39. through which fluid maypass from the tube to chamber 18 when the valve 34 is open, as willpresently be described. 7

The cap contains a vertically extending chamber 40 enlarged at its lowerend to provide the shoulder 41. Slidable in the enlarged portion ofchamber 40 for vertical movement l mited by the shoulder 41 is a cup 42,seating an expansion spring 43 engaging at its upper end a thrust .plate44 adiustable by set screw 45 which extends through the top of the capand held in adjusted position by a lock nut 46. The spring 43 tends toexpand the diaphragm 20 downwardly to push the pin 35 against the valveball 34 to open the valve and provide flow through chamber 40 to thecoil.

Opening through the cap 9 from the chamber 40 is a port 47 through whichthe chamber communicates with a vertical channel 48 into which isthreaded the end of a vertical conduit 49 leading to and communicating"with an annular chamber 50 within a housing 51 on the return line 4adjacent the outlet end of the coil 3.

The port 5'47 also provides comm "cation with a port 52 into which thenip le 53 of a valve housing 54 is connected, t e housing containing aneedle valve 55 operable against a seat 56 to control flow of flu1dthrough the port 52, the valve having a threaded steam 57 engaged withthe housing for operating the same.

Suitable means are rovided for sn 1 an ex ansible fluid t8 the condenseja c li and c amber 40, and preferably from the supply line. For thispurpose a nipple 58 communicating with the interior of the housing isthreadedly connected with a tube 59 engaged with the inlet side of thebody 8 and communicating with the screen chamber 10 therein, the needlevalve 55, therefore, controlling flow of fluid from the supply line intothe chamber 40, and into conduit 49 and condenserjacket 51.

The expanding fluid moves the diaphragm I to displace the valve; and ispermitted pass through the cup to spread over the upper surface of thediaphragm when the same is moved downwardly, by the provision ofopenings 60 in the bottom of the cup 42.

An indicator 61 is interposed in the conduit 49 for indicating thepressure of fluid in the conduit, jacket and chamber 40. The conduitpreferably comprises upper and lower sections respectively connectedwith the condenser jacket and the valve 7, and joined by a coupling 62,for convenient installation.

Further important characteristics of the control mechanism, whichinfluence the method of control, will be disclosed in the course ofdescription of operation, for example, the relative size of the conduit49.

In the operation of a system equipped with my improved control means,the system is assumed to be empty, and the springs 32 and 43 adjustedfor effecting a desired response of the control mechanism to theconditions of the refrigerant, and to properly balance the pressureinfluence of the incoming refrigerant which tends to close the valve.The condenser jacket and chamber 40 are provided with an expansiblefluid, preferably from the supply line. The hand valve 6 is closed, andrefrigerant is delivered to the supply line. The needle valve 57 is thenopened to admit fluid through the port 52 to supply the chamber 40 andcondenser jacket 51. When the presence of a sufficient supply ofexpansible refrigerant is indicated by the indicator 61, the port 52 isclosed by the needle valve, and the hand valve 6 is opened to permitrefrigerant to flow through the coil. The initial temperatures of thefluid confined in the conduit, and of the outgoing readjusted, causeopening of the inlet valve to permit refrigerant to enter the coil.

The refrigerant expands while in the coil and passing therethrough, andtakes up heat from the coil. The temperature of the refrigerant passingthrough the portion of the return line adjacent the coil outletinfluences the temperature of the fluid in the condenser jacket andcauses expansion or contraction of said fluid, the fluid correspondinglyinfluences the diaphragm 20 which is operatively engaged with theinlet-controlling members including the ball valve 34.

Expansion of the fluid due to relatively high temperature of thedeparting refrigerant causes pressure on the diaphragm and tendency tourge the ball valve away from its seat against the retaining influenceof the spring 32; and contraction of the fluid due to relatively lowtemperature of the departing refrigerant causes relief to pressure onthe diaphragm to permit the spring 32 to close the inlet and shut oflthe supply of refrigerant to the coil.

.The supply of refrigerant is, therefore, accurately and automaticallyincreased or diminished according to the demand of the coil, andsuitable to the preliminary adjustments of the springs 32 and 43.

One possible handicap exists, however, to efiicient and prompt responseof the valvecontrol means to temperature changes of the departingrefrigerant, namely, the pressure influence of the refrigerant adjacentthe coil inlet that may. be exerted upwardly against the diaphragm 20.Said pressure influence might oppose the fluid pressure above thediaphragm sufliciently to permit the valve to be closed by the spring32. Such interference is avoided, however, by the fact that as thepressure of the expanded fluid in the jacket tends to increase, so doesthe temperature of the refrigerant increase. Advantage is taken of thiscondition, and exchange of heat occurs by conduction through thediaphragm between the fluids above and below the diaphragm, therebyestablishing a balance of temperature and pressure between the twofluids.

In other words, when the rising temperature of the refrigerant tends toproduce resistance to the fluid above the diaphragm, heat is transferredto the fluid through the diaphragm, the pressure of the confined fluidin the chamber 43 is proportionately increased, and the fluid continuesto govern the valve.

Attention is particularly called to factors which make possible thestabilization of control by the fluid influenced by the departingrefrigerant. The jacket must be located above the valve, for drainingthereinto, and for eflicient action of the fluid therein. The conduitbetween the jacket and the valve must have suflicient area to permitfree exchange of temperature between the jacket and the chamber 40, bythe natural tendency of heated gases to move upwardly and of cooledgases to move downwardly.

A substantial area of the diaphragm should be exposed to the refrigerantand to the actuating fluid. The members should be so related that thedescribed exchange of heat between the fluid and the refrigerant cantake place.

The device illustrated and .above described sure chamber and engagingsaid diaphragm for operating said valve.

In testimony whereof I aflix my signature.

\ JOHN F. HOFFMAN.

